#include <stdio.h>
#include <unistd.h>

int main(int argc, char *argv[])
{
	pid_t pid;
	printf("%d\n", pid);
	if(pid < 0)
		printf("create error!\n");
	else if(pid == 0)
		printf("this is a sub-process\n");
	else if(pid > 0)
		printf("this is the parent process\n");
	else
		printf("I do not know what means...\n");
	return 0;
}
